Sieves for sludge draining



June 30, 1959 E. RIEDEL v 2,892,546

SIEVES FOR SLUDGE DRAINING INVENTOR. XE/UH 215026 BY WWW zrrazms'y June 30, 1959 Filed Feb. 21, 1955 E. RIEDEL 2,892,546

SIEVES FOR SLUDGE DRAINING 2 Sheets-Sheet 2 tats SIEVES son srunnu D! a r lNG Application February 21, 1955, Serial No. 489,548 In Germany @ctober 27, 1949 Public Law 619, August 23, 1954 Patent expires October 27, 1969 3 Claims. (Cl. 210-332) The present invention relates to improvements in sieves used for the drainage of sludges, especially fine coal sludges, or other similar goods, and generally for the separation of liquids from solid components.

Known sieves for these purposes are horizontally arranged, so that the goods fed to the sieve remain lying at the place of admission and have to be distributed on the entire surface of the sieve by rotating the latter. This results in an uneven stress on the sieve and the effect is likewise uneven. Furthermore, the distribution of the goods to be sieved over the surface thereof requires additional mechanical means, which make the device complicated, require additional sources of power, and often create disturbances.

The present invention is based on the discovery that the effectiveness of the sieve in the form of a frustoconical shell depends to a high degree on its inclination with respect to the horizontal and that by providing stepped inclines, not only the efiectiveness of the sieve, but also the distribution of the materials to be sieved may be highly improved. The effectiveness is actually raised to a different magnitude.

The invention therefore provides, for sludge-draining devices, sieve inserts of frustoconical or pyramidal shape which are subdivided in radial direction, so that each subdivision has one or more steps with a difierent inclination toward the horizontal.

The efifectiveness of the sieve and the distribution of the material is already considerably improved, when the surface is once buckled or bent in a manner by which the upper and outer part of the sieve has a different inclination than the lower center part. The efiectiveness may be still more increased by providing several bends. More particularly, a sieve surface curved parabolically gives very satisfactory results. However, other curved shells with increasing tangential angles will also be very useful.

In the accompanying drawings, examples are given showing the arrangement of sieve inserts of different shapes, according to the invention. However, it should be understood that these examples are given by way of illustration and not of limitation and that many changes in the details may be made without departing from the spirit of the invention.

2,892,546 Patented June 30, 1959 In the drawings:

Fig. 1 illustrates one longitudinal section of a sieve according to the invention;

Fig. 2 is a top plan View of this embodiment;

Fig. 3 is another embodiment of the same device, likewise in longitudinal section.

Referring to Figs. 1 and 2, a frarne structure is generally designated by F, the sieve by S, a container for the drained liquid by T, and a liquid drain pipe by M; the two conical shells are l and 2, respectively. Supported on the frame structure is a flat feed plate A for the sludge, through whose lower outwardly slanted flange R, the sludge is fed to the periphery U of the drainage surface S of conical shell 1. The angle of the frustoconical shell 1 with respect to the horizontal is smaller than the one which the two shells form with respect to each other. Due to this arrangement, in operation the goods which are fed to the periphery of the sieve from the outside in any desired manner, are made to travel toward the center and down over the shell 1 with comparatively low velocity and with removal of a large part of the liquid to a space surrounding the sieve. After the goods reach the funnel 2, they slide over shell 2 with greater speed while the rest of the liquid is drained by the sieve area. The drained material leaves the device by a pipe P, which is separate from the pipe system for removing the liquid.

In Fig. 3, an example is given for a configuration of the sieve area without sharp bends.

in Fig. 3, the curve C of the sieve S is continuous, concave and parabolic.

What I claim is:

1. In a drainage device for the separating of solids and liquids, particularly for the drainage of fine carbon sludges, a sieve having a funnel-shaped drainage surface and an open center, wherein the goods are fed to the sieve from the periphery and made to travel toward the open center and down, whereby liquid is drained through the sieve, while drained solids are discharged through the center opening, said sieve comprising a surface of increasing inclination in radial direction toward the open center of the sieve.

2. A device according to claim 1 wherein the incline of the sieve surface toward the center opening is proceedmg 1n successlve zones.

3. A device according to claim 1, wherein the incline of the sieve surface toward the center opening is proceeding in a continuous curve with increasing curvature.

References Cited in the file of this patent UNITED STATES PATENTS 80,666 Rich Aug. 4, 1868 1,000,086 Goetz et a1. Aug. 8, 1911 1,567,937 Galarneau Dec. 29, 1925 1,688,846 Andrews Oct. 23, 1928 1,855,904 Brown et al Apr. 26, 1932 2,385,162 Richardson Sept. 18, 1945 FOREIGN PATENTS 840,373 Germany June 3, 1950 

